Guess the Number - Math Riddle

Explanation :  

The pattern is,
First Method,
1*4+1  = 5
2*5+2  = 12
3*6+3  = 21
11*8+8 = 96

Second Method,
1+4=5
2+5=12
3+6=21
4+7=32
5+8=45
6+9=60
7+10=77
8+11=96